24"x48" stator at 3/32nd gap....

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24"x48" stator at 3/32nd gap.... 2 micron film. Lexan clear spacers.

What kind of performance can I expect if these are powered correctly and (obviously) built correctly?

By the way... my first post... Hello everyone!

I would like a somewhat powerful but not party level loudness. Basically a system capable in an average smaller living room of playing very distortion free choir and symphonic music. I do not have to blow the doors off.

I would like to cross at 80-90 hz if possible. The sub will be a down firing sealed unit in corner of room.

These will be as transparent as possible. Jazzman has referred me as a couple of ESL experts are said to reside here... ;-)

Have read over quite a few builds but want to do my own.

Thanks
 
Are you going with perf metal, cube louver, or what? I haven't built myself, but I've had several models of Acoustat, all of which used 9" x 46.25" panels, with some models also incorporating 8" x 46.25" panels. As Acoustat added panels to create wider speakers, they angled the panels relative to each other. Sound Lab does essentially the same thing, although they go about it quite a bit differently than Acoustat did. That neither of them simply used a single, wide panel should tell you something.

Good luck, whatever you decide to do. Keep us posted on your results.
 
Yes. Two panels indicates a probable roll off of high frequencies? I was thinking of adding a backfiring dome tweeter to aid in widening as the high frequencies are the fastest to fall off. Acoustat panels of that size go down to 250hz and I am wanting to cross at 80hz. Their is a severe roll off of highs in any concert hall. A natural sound with electrostatic clarity might be nice and well... more natural sounding. I have not ordered any metal but have ordered my Lexan and the Mylars and glue at this point. How do backfiring tweeters effect soundstage and imaging and the like? Was that just a fad from a decade or more ago? No cross up high is still the goal.
 
Acoustat panels go FAR deeper in the bass than 250Hz, I don't know where you got that figure. Almost every Acoustat model ever made were full-range electrostatics, no crossover or woofer at all. I've gotten real 20Hz response in my room from Acoustat panels alone. I think a single 9" Acoustat panel might be sufficient if an 80Hz crossover were used. But, enough about Acoustat.

I can't imagine any reason you'd need to add a tweeter to a 'stat. Properly done, an ESL should have excellent HF response without any supplement from a dome. Kinda contrary to one of the main selling points of ESL: coherence due to no crossovers or merely a single LF crossover point. Using two panels should not cause any HF rolloff.

I haven't heard Jazzman's ESL project, but they look awesome and apparently sound as good as they look.
 
There are some one inch dome tweeters which have an Fs or around 600 Hz and are crossed under 1KHz. that ought to tell you something. The 0ne plus 0ne is Acoustat`s best speaker in terms of stage and image. I guess that you need to prove this to yourself so build what ever seems good to you listen and find out for yourself. Wide palels will sound great but you will need a vise to clamp your head in while you listen to them. The larger your panel the harder it will be to drive. Why don`t you start with a 6 inch wide line source 7 ft. ten inches tall first and see what you think? Then if you want to go larger try 8 inches wide. 0ne plus 0nes can make good bass when driven by an amp that can actually carry the load and not take a fit. The larger the panel the harder it will be to find an amp which will work and sound good doing it. Lots of good amps will run a stat panel but few actually sound really good doing so. Do yourself a favor find a set of 0ne plus 0ne`s or Two plus Two`s and give them a listen before you build. The information that you have on these speakers is not correct. Acoustat`s remain as one of the most successful (if not the most sucessful) full range stat panel ever brought to market. I know that Jim Strickland really knows a thing or two. Listen to the competition and find out what you are up against. A lot of great R&D has gone into many products so take advantage of it and save yourself a lot of hard work. Best regards Moray James.
 
Well to be clear it was an Acoustat model 9 x 30 ish panel that was built to add the sub. A hybrid. The specs are on the sell page for the unit and 250hz is listed as the low. I am glad to hear your thoughts on not needing a tweeter. Any body ever figured out how Martin Logan bends theirs.... the air press method? Or is it really a man with a Jack Daniels t-shirt and barrel hitting the stators which are referenced in the literature as "a breakthrough gaseous biological pressing machine able for the first time to mimic the human movement conceived by evolution." I would like a slight bend but it must be difficult - a shop could do it... anyone have it done?
 
The real Acoustat went out of business years ago; that's a Chinese company that bought the name. Look for 1+1, 2+2, Model 3 & 4, Spectra, Monitor 3 & 4, Model X, etc. They are older speakers, but there is a general consensus that the original Acoustat's panels are probably the longest lasting, most indestructible drivers ever sold. Sorry to go on and on about Acoustats, but you can find used Acoustats for surprisingly low money, and there is a lot of info on the web about them, making them a great way to learn about electrostatic technology first-hand. They sound great, too. :)
 
Are you considering this as a bass only panel?

Using 2mil material for a diagphram is quite thick may/will yeild poor high frequency performance.

It is possible that it could also limit the lower end response as well as the material is heaver and will require more drive in order to move it as well as the tension using a thicker material could limit the amount of excursion.
I have some thicker stuff but I have not tried it yet,But have tried various thickness of films from .06 mil to 1 mil and they all worked but the thinner the material the better the midrange to high end detail.

I have documented this effect in another thread while doing a rebuild of my little panel and the added mass of a thicker coating aswell as the dirt and crud on the diagphram had a profound effect on the way it sounded overall even though it sounded good before the new diagphrams were installed.

Inorder to get bass out of a panel requires two major components, Surface area and Excursion.

Generaly a 100:1 D/S ratio is the norm but I have been using 150:1 to 200:1 on my small panel (3.25" : .070" ) to allow for large excursions.
It plays very nicely down to 200hz to 300hz at high levels using a bias of 6.5kv and any lower than that clipping of the diagphram to the stator becomes very noticeable.
I also had similar issues with my 8.75" wide panel using .093" spacer below 100hz,but at 200hz it was fine although I have not messed with them since a had built them in 2003.

The 100:1 D/S is pretty much a minimum figure in order to achieve mechcanical stability
of the diagphram as I had a hard time getting .0625" spacer to work on the 8.75" wide panel until I got enough tension to keep it from sucking into the stator as well as stator slapping problems and I could not allow in bass below 150hz to 200hz at high levels.

I too have contemplated such a design many times strictly for bass and I would suggest not using a D/S spacing of more than .125" to .150" due to the increased voltages required to properly drive the panel,But this is something that needs to be explored more for sure.

Ultimately I see people who go through such an extent to build such large panels end up adding subwoofers for below 100hz anyhow.

The beaming quality of such a wide Diagphram will be quite extreme at even the midrange frequency's and segmentation is something that should be considered if you plan on a full range panel.

I will be trying this technique on my next 11.5" wide X 3' tall panel crossed over around 200hz with 2 or 3 8" subs as a standalone unit.

Currently I am building a 5.5" x 4' x 2 (8ft. tall) pair to target the 250hz and above range that should work nicely with my current woofer system (4 X 12's and 4X 10's) in this particular room (10.5' X 18.5') on the short side.

Again using .093" (150:1 D/S) spacers.

This should cut down the beaming abit until 10khz to 15khz and above this I have difficulty hearing anyway and allow for plenty of room for excursion at the low end.
Being that this is such a narrow room a little bit of beeming is invitable to combat the first reflections at least until a get some room treatment done as my listening position is 12 to 14 feet from the speakers.
This also equates to a loss of aprox. 10db at the listening position.

Room dimensions is also something that you must consider when working with dipole speakers as well as subwoofers.

I have a set of Apogee Duette's and they just don't sound good at all in this narrow room as I don't have the space to set them up.
They need to be a minimum of 2' to 3' from the wall.

The last room I had them in was 14' X 23' set up on the long side and was heavily treated from reflections and the sound was not loud but the quality was incredible!


I hope this helps you get some idea's as to what you are trying to achieve.


Keep on DIYing !!!!

jer :)
 
I meant to say 2 micron is what I ordered... I thought this was really thin for an ESL as some were using 6 micron. I have learned the thinness is really a matter of debate. I am getting a ton of good info on this sight and grateful for all of it. The only way though is to do it in the end with caution I guess. The real ignorance for me is going to be the electrical. I will cheat and do an active purchased cross. The voltage I have already found. But I don't understand it a great deal other then the basic action. I think I am going to add a tube processor within the chain. For some reason I think this will be nice. I am going curved metal or wire I have decided. Have multiple designs I have done and looking at. I will do 3/32nd as that is what I have ordered and seems a reasonable middle. I will read more of your post but now my heart is giving out as it is 3am! Thanks! get back to you...
 
I screwed up and ordered the wrong thing... saw 2 micron and then .002 on tap and figured for some reason it was the same thing... I am at 58 microns I have learned which is way to thick so I will send it back. I will just order the 2um or 6um stuff from the guy on ebay. Taiwan... man that seems like that could take forever to get here... hmmmm Thanks for alerting me to this geraldfryjr!
 
I am currently using .25mil mylar (6micron) X 12.5" and it is very hard to find and the thinnest I have is .06mil (1.5micron) and the widest that I could find it (cheaply) was 3".
Chemplex had sent me a sample of it and I have used it in my micro driver using old credit cards for spacers breadboard material coated with aluminium foil tape as a stator.
I have not tested this driver any more other than it worked and sounded great for a headphone as it was only using 500v for a bias and an old EL34 OPT to step up the voltage.

There was a slight discussion last year about being able to use such a thin material for such wide spans (widths).

This material would be super for tweeter sections as because of its thinness and very low mass.

But, I am scepticale as if it is possible for it to retain its tension or even get enough tension to stay stable at spans up to and over 6" as it is quite strechty due to its thickness (if it can be obtained in wider widths).

My panels were designed to be able to take them apart and replace the frames with various thicknesses and types of diagphram materials.
I have even used model airplane coverings with great success as well.
But the thinnest material seemed to give the highest detail when it came to the higher frequency's (as expected).

I have done extensive research trying to find resources for such material back in 2003 and was when Dupont had decided to stop making anything less than .5mil here in the states.
So yes it is availible but at a great cost and from over sea's.


jer :)
 
I have in the workings a 11" X 17" diagphram panel just to check the stability of my .25mil( 6micron) mylar so I guess I better get building it!

I am guessing that this will be the limit for this material.
I am hoping that it will work as it worked on my 8.75" wide by 22" long panels.
I did have problems getting enough tension on them as I use the heat method and I was scared of burning a hole in them (this I have done many times).

But, I did finely get them to work as there were other issues along the way that I had to work out as well.
Problems with the stator coating and the flattness of the stators in some spots as well as a very high bias voltage.

The problem mainly was that I used a spray paint with a white pigment of Titanium Dioxide and this stuff is conductive and I couldn't get much more of a voltage of about 2.5kv to 3.2kv without some kind of arc occuring and disrupting the sound.
Minor problems that I have since worked in my technique of construction.

So, they didn't get screaming loud like my little panels do, but the quality just floored me!

All of my next builds will be done with acrylic clear as the coating.
I am not sure if you are aware of this but I use aluminium window screen for my stators. he,he
It is much more labor intensive but they cost next to nothing to build. :)

jer :)
 
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